The third book of the Winternight Trilogy is a satisfying finale to what came before and also an engrossing exploration of Russian medieval history, religion and folklore. Vasya, the witch of the title, has saved Moscow once, and must do so again in this book, now from the threat of war with the tatars, the one-time invaders from the Far East who hold power among the divided fiefdoms known as The Rus. They are marching on Moscow, and only the combined efforts of its human warriors and the magical beings all around them can possibly save Moscow from destruction. But after centuries of neglect and dismissal, can Vasya possibly get those arcane forces on her side? Only a quest deep into the Midnight lands and bargaining with the immortal beings who live there can provide an answer. And somehow she must gain the help of both the Winter King and his equally powerful brother, mortal enemies. Plus she must deal with her first tormenter, Brother Konstantin, a holy man seduced by evil. It all comes together on the battlefield in a grand finale that is exciting and terrifying, and the conclusion is well worth the journey. What I liked best about this series is the things I learned about the magic and history of a part of the world I knew so little about before, but the characters, ideas, and storyline are all excellent.